The invention relates to a device for removably fastening a first part, which is particularly a covering element, to a second part installed in a vehicle and particularly in an airplane. This second part comprises an L-shaped element and a support element arranged substantially flush with the shorter leg of the L-shaped element and spaced from the L-shaped element. Particularly, the second part is a C-shaped fastening profile comprising a base leg and two side legs having their free ends oriented towards each other.
In an airplane, the covering elements or functional panels (also referred to as passenger service unitsxe2x80x94PSU) arranged above the seats are fastened by use of special fastening elements to fixed C-shaped profiled rails arranged in the airplane. These rails comprise a base leg having two mutually spaced side legs extending therefrom at an angle of 900 and in parallel to each other. On the free ends of the side legs, the latter are deflected to face each other, resulting in a substantially C-shaped structure when viewed in cross section.
Fastening elements for attachment of covering elements and functional panels to a rail system as described above are known e.g. from DE-A-197 30 269.6 DE-A-100 63 035.9; WO-A-00/40436; WO 0040436A; DE 197 30 269 A; U.S. Pat. No. 4,591,204 A; JP 2002/067856; and DE 91 10 175 U1.
In the known fastening systems, use is made throughout of metal elements so as to guarantee an attachment which is safe from undesired movements in the direction of the rails. In an airplane, however, a large number of such fastening elements are used (up to 2,000 pieces depending on the type of the airplane). As a consequence, the mounting of the fastening elements should be performed relatively quickly and reliably. Apart from that, the weight aspect is of eminent importance in an airplane.
It is an object of the invention to provide a fastening system to be used particularly in airplanes which is of a light weight and can be mounted and dismounted at a reduced time.
For achieving the above object, there is proposed according to the invention a device for removably fastening a first part, particularly a covering element, to a second part installed in a vehicle and particularly in an airplane and comprising an L-shaped element including a first leg and a second leg extending therefrom substantially at a right angle and having a free end, and comprising a support element arranged in the extension of the second leg and at a distance from the free end of the second leg. The second part is particularly a C-shaped mounting profile.
According to the invention, the device for fastening a first part to a second part of the above described type comprises
a fastening element having a first end for attachment to the first part and a second end for attachment to the second part,
wherein the second end of the fastening element is provided with
an abutment portion for abutment on the second leg and the support element of the second part,
a locking portion to be locked to the free end of the second leg of the second part, the locking portion being flexible and adapted to be moved, while generating a restoring force, from a locking position into a release position,
an actuating portion for manually moving the locking portion from the locking position to the release position thereof, and
a grip-around portion for gripping around the second part in the transition region of the two legs.
The device according to the invention comprises a fastening element which is of a one-pieced configuration. This fastening element is preferably made from plastic while particularly a thermoplastic material will be useful. The production of the fastening element is performed through injection-molding technology.
The fastening element is provided with a restorable locking portion which, when in its rest position, assumes a locking position and can be moved into a release position while generating a restoring force particularly by elastic deformation. The locking portion has a locking projection gripping around the free end of the second leg of the L-shaped element of the second part, while a grip-around portion is arranged to abut the (outer) side, facing away from the second leg, of the first leg of the L-shaped element. The fastening element is further provided with an abutment portion provided to abut both on the second leg of the L-shaped element and on the support element of the second part. Thus, the abutment portion bridges the region between the L-shaped element and the abutment element of the fixed second part. This abutment serves for protection from twisting and thus provides for a positionally stable abutment of the fastening element to the second part in the locked condition.
To make it possible to transfer the locking portion from its locking position to the release position, the fastening element of the inventive device is provided with an actuating portion. This actuating portion is preferably arranged in the extension of the locking portion.
The handling of the fastening element of the inventive device is as simple as reasonably conceivable since it is merely required to introduce the fastening element by its locking portion between the L-shaped element and the support element of the fixed second part where, after complete insertion, it will be automatically locked to the second part. This locking can be acoustically verified so that the operating person will receive a confirmation that the fastening element has reached its locking condition. When mounting the fastening element, the L-shaped element will be confined on both sides, i.e. on one side by the locking portion and on the other side by the grip-around portion. With the fastening element fully inserted, the abutment portion is in abutment on those sides of the L-shaped element and the support element of the fixed second part which are facing towards the abutment portion. This abutment is suitably effected under (slight) elastic deformation of the abutment portion, which is of advantage under the aspects of a compensation for tolerances and particularly variations of thickness as well as oblique orientations of the fastening profile (of the second part).
According to an advantageous modification of the invention, it is provided that the locking portion is connected via a holding portion to the abutment portion of the fastening element. This holding portion extends from the abutment portion and in the mounted condition of the fastening element is arranged between the L-shaped element and the support element of the second part. The actuating portion is formed as an extension of the locking portion and arranged to project beyond the abutment portion. The connection region of the locking portion to the holding portion is thus located at a distance from the abutment portion (notably by the holding portion). The connection between the holding portion and the locking portion is flexible and adapted for torsional deflection, respectively, so that the restoring forces biasing the locking portion into its locking position will be generated when the locking portion is moved into the release position.
According to an advantageous modification of the invention, it is further provided that the grip-around portion extends from the abutment portion and that, particularly, the abutment portion, at a position opposite the grip-around portion or near the grip-around portion, has a web portion extending there-from which is arranged to face away from the grip-around portion, with the free end of the web portion being connectable to the first part and particularly forming the first end of the fastening element. According to the present modification of the invention, the grip-around portion is rigidly connected to the abutment portion. Likewise rigidly connected to the abutment portion is the web portion which forms the connection to the first part.
Preferably, the fastening element of the inventive device comprises two web-like abutment portions, each of them having a grip-around portion and a holding portion extending therefrom; between adjacent abutment portions and holding portions, the locking portion is arranged which can be moved about a (virtual) pivoting axis and is integrally connected to the holding portions. Both abutment portions suitably have a web portion extending therefrom, and the parallel web portions are partially connected to each other, thus increasing the stability and also saving material.
As already mentioned above, the inventive device is distinguished by its simple construction and its easy handling during the mounting and dismounting processes. As a result, the costs for production and assembly alike are low. While an undesired detachment of the fastening element from the second part is precluded by positive engagement (the locking portion or the locking hook grips behind the L-shaped element of the second part - undercut principle), the fastening element is on the second part secured along the extension thereof only through frictional engagement to preclude undesired movements. Such undesired movements are generally not allowable in airplane-covering elements or functional panels (PSUs) arranged above the seats since these elements must be secured against movements in flight direction (so called X-stop). The inventive fastening element should thus be used in ceiling coverings in which some covering elements are attached by the inventive device and the other covering elements are attached by the fastening system with X-stop. Therefore, the inventive device is particularly suited for the attachment of the so-called in-fill panels and O2 panels above the airplane seats. Notably, depending on the spacing between the seat rows, the interspace between adjacent PSU or 02 panels has to be filled by one or several identical or different in-fill panels. For this purpose, the PSU and O2 functional panels are attached by means of fastening elements which will also guarantee a reliably safe securement in flight direction. If, then, adjacent to the PSU and O2 functional panels, the in-fill panels are fixed by use of the inventive device, the PSU and O2 functional panels will, as it were, take over the X-stop function so that the fill-in panel attachments do not necessarily have to assume this function themselves anymore.
Further, the inventive device can be used e.g. for one or a plurality of fastening profiles of the PSU and O2 functional panels so that the rest of the fastening profiles of these functional panels should be provided with the X-stop function.
Of course, the invention is not limited to uses in attaching the in-fill panels in airplanes. Instead, the inventive device is useful for basically all covering elements or other elements in vehicles. Thus, the invention is of a general applicability.
The advantages of the inventive device can be summarized as follows:
The fastening element according to the inventive device can be produced as one (injection-molded) member and does not comprise any further mechanical components and particularly no moveably supported components.
When plastics are used, the fastening element can be given an extremely light weight and be produced at low cost.
Already during the mounting, the worker will receive an acoustic conformation as a verification that the fastening element has been locked to the second part.
By simple manipulation of the actuating element (e.g. using a screw driver or the like hand-operated tool), the locking state can be released in a well-aimed manner and the fastening element can thus be dismounted.
The self-locking mechanism of the fastening element will also function in case of variations of the wall thickness caused by tolerances and in case of an oblique orientation of the second part.
When mounting the fastening element, the protective surfaces of the elements of the second part will not be damaged because the locking portion will move easily along the L-shaped element of the second part.
By selection of suitable plastics and particularly by the use of thermoplastic materials for the fastening element (and by use of metals for the second part), high reliability and longevity of the locking mechanism will be obtained.